Troubleshooting:
Make sure to have layeredFS set up on your console or else themes won't show up.
Sx os doesn't require you to have the "sxos" folder on the root of the sd, but if you don't have it the installer won't detect sx os. So if you use sx os and don't have a folder called sxos on the sd, manually create it.

SZS files are illegal to share, don't post them here on gbatemp. You can only post nxtheme files.